Heat dissipation fan

ABSTRACT

A heat dissipation fan includes a fan blade body having a shaft mounted thereon; an inner assembly installed within the fan blade body, the inner assembly comprises an iron casing, a ring-shaped permanent magnet installed inside the iron casing, a stator bobbin with the winding of a coil thereof, and a sleeve installed in the center of the stator bobbin, and within the sleeve there are mounted a ball bearing and a lubricating bearing under the ball bearing, and wherein an upper end of the ball bearing abuts against an O-ring and a lower end of the lubricating bearing abuts against a C-type clamping ring, and wherein a lower end of the sleeve is securely mounted on a circuit board and a base; and a magnetic device installed on the base in a position corresponding to a lower end of the shaft to attract the shaft.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a heat dissipation fan, and moreparticularly, to a heat dissipation fan having an additional magneticdevice to reduce noise and prolong the life of the heat dissipation fan.This invention features this additional magnetic device that permitsinverse or declined operations of this heat dissipation fan withoutaffecting the total height of the fan. The magnetic device alsointeracts with the ball bearing and C-type clamping ring installed onthe shaft of this heat dissipation fan

[0003] 2. Description of the Prior Art

[0004]FIG. 1 and FIG. 2 illustrate a prior art heat dissipation fan 20.As shown in FIG. 1 and FIG. 2, the prior art heat dissipation fan 20includes a fan blade body 7. A chamber 71 is formed in the fan bladebody 7. A shaft 72 is fixed at the center of the fan blade body 7. Aninner assembly 8 is fittingly mounted within the chamber 71. The shaft72 is inserted in the inner assembly 8. The fan blade body 7 can rotatedue to the interaction between the components installed in the innerassembly 8. Typically, the inner assembly 8 includes an iron casing 81,a ring-shaped permanent magnet 82 installed inside the iron casing 81 tobe a rotor, a stator bobbin 84 with the winding of a coil 83 thereof,and a copper sleeve 85 installed in the center of the stator bobbin 84.Within the sleeve 85 there are mounted a ball bearing 86 and alubricating bearing 87 under the ball bearing 86. The upper end of theball bearing 86 abuts against an O-ring 88 and the lower end of thelubricating bearing 87 abuts against a C-type clamping ring 89. Thelower end of the sleeve 85 is securely mounted on a circuit board 201and a base 202.

[0005] However, the prior art heat dissipation fan 20 encounters severalproblems. First, when assembling the prior art heat dissipation fan 20,a gap is formed between the iron casing 81 and the fan blade body 7.This results in the movement of the fan blade body 7 along the axis ofthe shaft 72, thereby changing the total height of the fan duringinverse or declined operations. Another shortcoming of the prior artheat dissipation fan 20 is that rollers installed in the ball bearing 86cannot roll in the same level, and hence the life of the heatdissipation fan 20 is limited. In addition, the irregular rolling of therollers in the ball bearing 86 generates aggravating noise. Further,during the inverse operation of the heat dissipation fan 20, the C-typeclamping ring 89 mounted on the free end of the shaft 72 may contact thelubricating bearing 87. The result is friction between the C-typeclamping ring 89 and the lubricating bearing 87, and thus deterioratesthe noise problem and of the fan.

[0006] To eliminate the weaknesses of the above conventional heatdissipation fan, the subject inventor has devoted extended efforts inintensive research and experiments, and has finally developed anddesigned the improved fan structure of this invention.

SUMMARY OF THE INVENTION

[0007] The primary object of the present invention is to provide animproved structure for radiating fans, relating primarily to anadditional magnetic device installed in the fan that is speciallyapplied to electronic instruments and computers.

[0008] Another objective of this invention is to provide an improvedheat dissipation fan with a magnetic device that can interact with theshaft and hence permits inverse or declined operations without affectingthe total height of the fan.

[0009] Still another objective of this invention is to provide animproved heat dissipation fan that has prolonged lifetime and reducednoise by the aid of an additional magnetic device. The magnetic deviceinteracts with the C-type clamping ring and keeps it from contacting thelubricating bearing during operations.

[0010] Still another objective of this invention is to provide alow-noise cooling fan having a magnetic device that can provide magneticforces to attract the shaft and rollers installed in the ball bearing.The rollers can rotate in the same level, thereby prolonging life of thefan and reducing noise.

[0011] According to the claimed invention, the heat dissipation fanincludes a fan blade body having a shaft mounted thereon; an innerassembly installed within the fan blade body, wherein the shaft isinserted in the inner assembly, the inner assembly comprises an ironcasing, a ring-shaped permanent magnet installed inside the iron casing,a stator bobbin with the winding of a coil thereof, and a sleeveinstalled in the center of the stator bobbin, and within the sleevethere are mounted a ball bearing and a lubricating bearing under theball bearing, and wherein an upper end of the ball bearing abuts againstan O-ring and a lower end of the lubricating bearing abuts against aC-type clamping ring, and wherein a lower end of the sleeve is securelymounted on a circuit board and a base; and a magnetic device installedon the base in a position corresponding to a lower end of the shaft toattract the shaft.

[0012] It is to be understood that both the forgoing general descriptionand the following detailed description are exemplary, and are intendedto provide further explanation of the invention as claimed. Otheradvantages and features of the invention will be apparent from thefollowing description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 and FIG. 2 illustrate a prior art heat dissipation fan.

[0014]FIG. 3 is an exploded diagram of the heat dissipation fan inaccordance with the preferred embodiment of this invention.

[0015]FIG. 4 illustrates a cross sectional view of the heat dissipationfan according to this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0016] Please refer to FIG. 3 and FIG. 4. FIG. 3 is an exploded diagramof the heat dissipation fan 10 in accordance with the preferredembodiment of this invention. FIG. 4 illustrates a cross sectional viewof the heat dissipation fan 10 according to this invention. As shown inFIG. 3 and FIG. 4, the heat dissipation fan 10 includes a fan blade body1. A chamber 11 is formed in the fan blade body 1. A shaft 12 is fixedat the center of the fan blade body 1. An inner assembly 2 is fittinglymounted within the chamber 11. The shaft 12 is inserted in the innerassembly 2. The fan blade body 1 can rotate due to the interactionbetween the components installed in the inner assembly 2. The innerassembly 2 includes an iron casing 21, a ring-shaped permanent magnet 22installed inside the iron casing 21 to be a rotor, a stator bobbin 24with the winding of a coil 23 thereof, and a copper sleeve 25 installedin the center of the stator bobbin 24. Within the sleeve 25 there aremounted a ball bearing 26 and a lubricating bearing 27 under the ballbearing 26. The upper end of the ball bearing 26 abuts against an O-ring28 and the lower end of the lubricating bearing 27 abuts against aC-type clamping ring 29. The lower end of the sleeve 25 is securelymounted on a circuit board 3 and a base 4.

[0017] This invention features an additional magnetic device 5 that isinstalled on the base 4 in a position corresponding to the lower end ofthe shaft 12. The magnetic device 5 comprises a permanent magnet 51 anda magnetic guide plate 52.

[0018] With reference to FIG. 4, when assembling, the iron casing 21 ismounted in the chamber 11. The ring-shaped permanent magnet 22 ismounted in the iron casing 21. The stator bobbin 24 with coil 23 thereonis then installed inside the ring-shaped permanent magnet 22. The ballbearing 26 and the lubricating bearing 27 are installed into the sleeve25. Thereafter, the sleeve 25 is mounted inside the stator bobbin 24.The O-ring 28 and the C-type clamping ring 29 are used to secure theball bearing 26 and the lubricating bearing 27, respectively, on theshaft 12. Finally, the magnetic device 5 comprising the permanent magnet51 and magnetic guide plate 52 is installed on the base 4 in a positioncorresponding to the lower end of the shaft 12.

[0019] In contrast to the prior art, this invention presents thefollowing advantages:

[0020] 1. After assembling the heat dissipation fan 10, the magneticdevice 5 will attract the shaft 12 so that the fan blade body 1 willremain in place during any type of operations, i.e., inverse operation,declined operations, or the like, without changing the total height ofthe fan.

[0021] 2. Since the magnetic device 5 can attract the shaft 12 themagnetic device 5 thus generates a force on the ball bearing 26. Thisforces the rollers in the ball bearing 26 to move in the same level. Theregular movement of the rollers in the ball bearing 26 thereforeprolongs the life of the fan.

[0022] 3. Since the magnetic device 5 can attract the shaft 12 a safespacing may be kept between the C-type clamping ring 29 and thelubricating bearing 27. The friction between the C-type clamping ring 29and the lubricating bearing 27 is thus eliminated.

[0023] Those skilled in the art will readily observe that numerousmodification and alterations of the device may be made while retainingthe teachings of the invention. Accordingly, the above disclosure shouldbe construed as limited only by the metes and bounds of the appendedclaims.

What is claimed is:
 1. A heat dissipation fan comprising: a fan bladebody having a shaft mounted thereon; an inner assembly installed withinthe fan blade body, wherein the shaft is inserted in the inner assembly,the inner assembly comprises an iron casing, a ring-shaped permanentmagnet installed inside the iron casing, a stator bobbin with thewinding of a coil thereof, and a sleeve installed in the center of thestator bobbin, and within the sleeve there are mounted a ball bearingand a lubricating bearing under the ball bearing, and wherein an upperend of the ball bearing abuts against an O-ring and a lower end of thelubricating bearing abuts against a C-type clamping ring, and wherein alower end of the sleeve is securely mounted on a circuit board and abase; and a magnetic device installed on the base in a positioncorresponding to a lower end of the shaft to attract the shaft.
 2. Theheat dissipation fan of claim 1 wherein the fan blade body comprises achamber for accommodating the inner assembly.
 3. The heat dissipationfan of claim 1 wherein the magnetic comprises a permanent magnet and amagnetic guide plate.